Electric water heater



Filed July 15, 1925' WIT Ess zf ATTORNEY Patented Mar. 15, 1927.

WILLIAM WILSON \VAINXVRIGHT, OF TACOMA, W'ASHINGTON.

ELECTRIC WATER HEATER.

Application filed July 15, 1925.

This invention relates to an electric water heater, primarily adapted tobe connected to a hot water supply tank for use in homes, restaurants,hotels and the like.

The general object of the invention is to provide a heater of this-type,which is strong and durable, which will heat the water quickly at a lowcost, and which will not readily get out of order. It comprises a closeddrum having its walls lined with magnesia, or other suitable heatinsulator, and containing the resistance element and water pipes,preferably of copper, which extend from top to bottom thereof. It isadapted to be connected either end up to branch pipes leadingrespectively from the upper and lower ends of the tank. The heatingelement is so arranged that by providing suitable switches andconnections different degrees of heat may be obtained.

The invention will be more specically described with reference to theaccompanying drawing, which illustrates the detailed con structionthereof.

In the drawing:

Figure 1 is a side elevation of the heater connected to a hot watersupply tank.

Figure 2 is a longitudinal section through the heater.

Figure 3 is a transverse section thereof taken on the line 33 of Figure2.

Figure 4 is a diagrammatic View showing the wiring connections by meansof which different degrees of heat may be obtained.

The invention is illustrated in connection with a hot water supply tank5, of the usual construction, having an inlet pipe 6, which dischargesnear the bottom thereof, and an outlet pipe 7 leading from its upperend. The heater comprises a centrally disposed pipe 8. preferably ofcopper, having threaded ends adapted to be connected by suitable unions9 and 10 to branch pipes 11 and 12, which are respectively connected tothe bottom of the tank 5, and to the outlet pipe 7 near the upper end ofthe tank. Two end caps 13 of iron or other suitable metal are adjustablysecured on the threaded ends of the pipe 8 by means of lock nuts 14. Therims of the caps 13 are chamfered at 15 to receive the ends of acylindrical sheet metal casing 16, which surrounds the body portion ofthe heater. The caps 13 are lined with magnesia 17, or other suitableheat insulating material, held therein by metallic disks 18, which bearagainst the ends of a lining Serial No. 43,820.

19 of similar material inside the casing 16. Brass nipples 20 areconnected to the pipe 8 just within the end caps 13, and are connectedby suitable brass fittings to the opposite ends of coiled copper pipe21, and serve to support the same within the casing. The heating elementcomprises a resistance coil 23 wound about a double sleeve of insulatingmaterial 22 which surrounds the pipe 8, and extends substantially fromone of the nipples 20 to the other. For supplying current to the coil 2binding posts 24 and 25 are secured to one of the metallic disks 18,from which they are insulated in the usual manner. The post 24 isconnected to the coil 23, near its middle, by a conductor wire 26. Theother conductor wire 27 leads from the post and has two branches 28 and29 connected respectively to opposite ends of the coil 23. Theconductors are suitably encased in insulating tubes 30. It will be seen,therefore, that the coil 23 is in effect composed of two sectionselectrically parallel, the current coming in through the wire 27 andbranches 28 and 29, and through the two sections of the coil 23 to thereturn wire 26. The heating coil is connected to the line wires of thecircuit by connecting wires 31 which pass through an insulating bushing32 to the binding posts 24 and 25, respectively.

If it is desired to arrange the heater so that different degrees of heatmay be obtained, itmay be wired as illustrated in Figure 4. In thiscase, the middle point of the coil 23 is connected by a wire 34 to thecontact point 35. One end of the coil 23 is connected by a wire 36 to acontact point 38, and the other end of the coil is connected by a wire37 to a third contact point- 39. The line wires 40 are connectedrespectively to the contact point 38 and a fourth contact point 41. Whenthe highest degree of heat is desired, the point 41 is connected by asuitable switch to the point 35, as indicated in dotted lines at 42, andthe point 39 is similarly connected to the point 38, as indicated at 43.The two sections of the coil 23 are then electrically parallel, and themaximum amount of current passes therethrough. If a medium degree ofheat is required, the connection between the points 38 and 39 is broken,so that the current passes through one section only of the coil. If thelowest degree of heat is required, the points 41 and 39 only areconnected, so that lll) both sections of the coil are in series, and theminimum amount of current passes therethrough.

From the foregoing description, it Will be seen that the heater is ofsubstantial construction, and so arranged that it may be connectedeither end up to the pipes leading to the tank, and may be installed inany convenient location. The control switch may be located either-nearthe heater or at a more distant point. lhe resistance coil is completelyenclosed Within heat insulating Walls so that the heater may be operatedwith the utmost economy. The heater may be easily installed, or easilydisassembled when repairs are necessary.

- Nhile 1 have shown and described in detail the preferred embodiment ofthe invention, it is apparent that various modifications may be madetherein Without any material departure from the salient featuresthereof, and it is my purpose, theretore, to include all suchmodifications within the scope of the appended claims.

What is claimed is:

1. In an electric Water heater, the conibination of a cylindrical casingmember, a central pipe section extending longitudinally through thecasing member, end caps mounted on the end portions of the pipe sectionand adjustable longitudinally thereof, the rims of said caps beingchamt'ered to receive the ends of the cylindrical casing member and tosupport the same, a pipe coil within the casing and connected to saidcentral pipe section near the ends thereof, and an electric heatingelement within the pipe coil and surrounding the central pipe section,the. ends or" said central pipe section projecting beyond the ends ofthe casing, so that after the heater has been completely assembled, theends of said pipe section may be connected to pipe sections leading to atank containing Water to be heated.

2. In an electric water heater, the combination oi acylindrical casingmember, a central pipe section extending longitudinally through thecasing member, end caps mounted on the end portions oi the pipe sectionand adjustable longitudinally thereof into supporting relation to thecylindrical casing member and forming closures for the ends thereof, twonipples connected to the central pipe section Within the casing and nearthe respective end caps, a pipe coil within the casing and connected tosaid nipples, an insulating sleeve surrounding the central pipe sectionand extending substantially from one nipple to the other, and anelettric heating element Wound about said sleeve Within the pipe coil.

In testimony, that I claim the foregoing as my own, I have heretoatlixed my signature.

WILLIAM WILSON WAINWR-lGHT.

